Once a cheater, always a cheater.
It's a warning that you should be wary of a serial cheater -- that people who aren't loyal to a partner will cheat again.
Whether you believe it's true or not, a new study linking dishonesty and the brain may explain why serial cheaters continue to commit infidelity.
The paper, titled "The brain adapts to dishonesty," claims each time a person lies, they feel less guilty about doing so.
It's all because of the amygdala, a region of the brain that provides a negative response when humans lie -- but every time we are dishonest, the response weakens.
The study states,
We speculate that the blunted response to repeated acts of dishonesty may reflect a reduction in the emotional response to these decisions or to their affective assessment and saliency.
Elite Daily spoke to Neil Garrett, a co-author of the paper and researcher at Princeton Neuroscience Institute.
He said the findings would need to be tested specifically on relationships to determine whether it applies to infidelity, but that a "similar mechanism could apply."
He told Elite Daily,
The idea would be the first time we commit adultery we feel bad about it. But the next time we feel less bad and so on, with the result that we can commit adultery to a greater extent.
What our study and others suggest is a powerful factor that prevents us from cheating is our emotional reaction to it, how bad we feel essentially, and the process of adaptation reduces this reaction, thereby allowing us to cheat more. With serial cheaters, it could be the case that they initially felt bad about cheating, but have cheated so much they've adapted to their ways and simply don't feel bad about cheating any more. Another possibility is that they never felt bad about cheating to begin with, so they didn't need adaptation to occur, they were comfortable with it from the get-go.
Essentially, those little white lies -- regardless of what they're about, and whether you tell them to your parents, boss or friends -- grow into more significant lies because we can deal with them better.
Or, of course, you're a raging sociopath with an inability to feel guilt about hurting someone you care about.
Garrett also said the study would need to be modified to assess the impact of cheating on the amygdala, adding,
I think one of the key differences would be that cheating in relationships often takes place over shorter timescales than in my study. So whether adaptation takes place at slower time scales and whether it generalizes to other types of behavior we find aversive like adultery, violence, etc are the key two things we'd need to test to start to answer this.
The authors behind the study came to their conclusion after an experiment that tested participants' capacity to lie.
People were shown a jar filled with coins and asked to help a partner, who was only given a blurry image, guess how many were in the jar.
But when they were told they would receive a financial reward if their partner overestimated the amount of money in the jar, they were more likely to lie -- prompting a response from the amygdala.